Brewing Iced Tea

Looking for some advice here... Adagio shipped me some of their new iced tea bags with my last tea order and I think I completely botched the brewing. Here's what I did:

Boiled 8 cups of water (bag said 1 pouch for 1 quart)Threw both pouches into the pot, added sugar, steeped for the directed five minutes.After steeping was finished I added some ice which promptly (obviously) melted... Are you supposed to wait before adding ice?I tasted the tea and found it tasted kind of bitter (and not at all mango)After the ice melted I put the tea in a pitcher and put it in the fridge to cool...

It would strike me as very strange if the tea suddenly un=bittered but I don't see how I could have burnt it considering the steeping temperature was supposed to be 212...